Designers of toothbrushes have sought to optimize the brushes so that they are better able to reach all of the teeth in the mouth. In this respect, much attention has focused on the angle of the toothbrush head to the handle.
Another issue concerning toothbrush use, although usually more associated with the manner of use rather than the toothbrush structure, is the direction in which brushing should be carried out. It has been suggested by some that brushing should be conducted in an up-and-down direction rather than from side to side. A possible advantage of the up-and-down motion is that this may decrease the likelihood that receding gums will expose sensitive areas at the base of the teeth. However, side-to-side brushing has the advantage that difficult-to-access areas toward the rear of the mouth are more likely to be subjected to the brushing action.
Del Rosario U.S. Pat. No. 4,333,199 discloses a toothbrush which is mounted using a coil spring interconnecting the brush base and handle. This is said to provide for a swinging, rotatable, tilting movement of the brush relative to the handle during use.
Bradley PCT International Publication No. WO 92/17094, based on the priority of U.S. application Ser. Nos. 677,656 and 745,892, is directed to a toothbrush which is said automatically to provide an up-down action in concert with a side-to-side stroking action. Numerous embodiments are disclosed. In the embodiment of FIGS. 1-5, for instance, the brush pad is pivotally attached with a hinge which comprises a rod-like member which is received within a receptor comprising an elongate groove. As the brush is stroked, the brush pads will rock outwardly or inwardly. In the embodiments of FIGS. 17 and 18, the pads slide within an elongate slide member disposed at an angle with respect to the longitudinal axis of the pad.